---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-23-237762"
form_type: "8-K"
ticker: "ATRA"
cik: "0001604464"
company_name: "Atara Biotherapeutics, Inc."
filed_at: "2023-09-20T23:59:59+00:00"
generated_at: "2026-06-10T12:03:31.592722+00:00"
event_type: "regulatory"
sentiment: "positive"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Atara announces FDA agreement on tab-cel comparability; BLA submission planned Q2 2024

## Summary
- FDA and Atara aligned on analytical comparability between manufacturing process versions of tab-cel.
- Alignment allows pooling of pivotal clinical trial data from different process versions for BLA.
- Atara expects to submit tab-cel BLA in Q2 2024, enabling inclusion of Phase 3 ALLELE data.
- Company also advancing U.S. partnership discussions for tab-cel commercialization.

## SEC filing metadata
- accession: 0001193125-23-237762
- form_type: 8-K
- ticker: ATRA
- cik: 0001604464
- company_name: Atara Biotherapeutics, Inc.
- filed_at: 2023-09-20T23:59:59+00:00
- event_type: regulatory
- sentiment: positive
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1604464/000119312523237762/0001193125-23-237762-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1604464/000119312523237762/d490760d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-23-237762
- JSON: https://secwatch.observer/filing/0001193125-23-237762.json
- Plain text: https://secwatch.observer/filing/0001193125-23-237762.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.